The process
Granulators, dryers and coolers in NPK, DAP and SSP plants release hygroscopic dust and ammonia or fluoride fume. Cyclones take the coarse dust, scrubbers take the gas, and the fans behind them are in stainless steel or lined construction.
The gas at the fan
Granulator and dryer exhaust carrying hygroscopic fertilizer dust and ammonia or fluoride fume. Corrosive and sticky; lined or stainless construction after a scrubber or bag filter.
Selection for this duty
| Blade form | Straight radial, open or shrouded, so the wheel can be cleaned and does not hold deposit |
| Material of construction | Stainless steel on all wetted parts, grade to suit the gas analysis |
| Drive and bearings | Direct coupled or belt driven; belt drive where the duty point may need tuning at site |
| Also specified | Access doors on the scroll and a wheel that can be cleaned in place; casing drain at the lowest point |
| Density at the fan | At about 90°C the gas density is close to 0.97 kg/m³, 81% of standard air. Pressure developed and power drawn fall in the same ratio, so the selection is made at this density and the motor is checked at cold start. |
The fan behind a bag filter, cyclone or multiclone on a dust extraction system. Placed on the clean side where possible so the blade can be chosen for efficiency. Client-stated blade types for the Dust Collector Fan in general: Backward inclined and radial tipped.
Industries
Other fans in fertilizer granulation plants
Dust Collector Fan in other processes
Bagasse Fired BoilersRice Husk Fired BoilersAFBC BoilersCFBC BoilersPulverised Coal Fired BoilersWaste Heat Recovery BoilersBiomass Fired BoilersThermic Fluid HeatersCement Preheater KilnsVertical Roller Raw MillsBall Mill Raw GrindingCement Grinding MillsClinker Grate CoolersCement Plant Coal MillsCement Packing and DispatchRotary Lime KilnsVertical Shaft Lime KilnsGypsum Calcining PlantsSponge Iron Rotary KilnsBlast Furnace Hot Blast StovesSinter PlantsCoke Oven BatteriesElectric Arc Furnace SteelmakingInduction Furnace Melt Shops
Services on this fan
Information needed to select or quote
- Duty point. Volume flow and static pressure at the fan inlet, with the gas density and temperature or the conditions to derive it.
- Operating conditions. Site altitude, normal operating temperature and continuous or intermittent duty.
- Gas stream. Dust loading and particle size, corrosive species, moisture, upset temperature and any tendency of the material to deposit on the impeller.
- Mechanical. Rotation viewed from the drive end, discharge orientation and motor power.